But in the past month, the heir to Pakistan's most famous political dynasty, has moved centre stage at the start of a journey many believe will see him eventually become prime minister.

The 23-year-old has discarded his low profile to chair party meetings and help formulate the government's response to Nato air strikes that killed 24 soldiers, according to a slew of official press releases and government photographs.

He was pressed into action while his father, President Asif Ali Zardari, lay ill in a Dubai hospital, leaving no one in any doubt that the eldest son of Benazir Bhutto was being positioned as a key vote winner in elections that could come in the year ahead.

Farhatullah Babar, the president's spokesman, said he was ready to take a more active role in Pakistan's politics.

"Now he has completed his education and is getting engaged in different political activities," he said.

He inherited the hopes of a country and the mantle of Pakistan People's Party chairman when his mother was assassinated in December 2007.

Since then he has avoided the limelight, concentrating on his studies. He graduated from Oxford with a 2-1 in history last year before enrolling at law school in London.

That changed with his father's illness and a growing sense of crisis, as the year ends with a swirl of rumours that the president could be toppled.

At the same time, the rise of Imran Khan's energetic campaign – he has been known to give interviews in shorts after returning from his daily run – has left Pakistan's established political dynasties searching for a more youthful image.

Cyril Almeida, a political commentator with The Dawn newspaper, said: "He also serves as a reminder that Mr Zardari was married to Benazir Bhutto which gives an unpopular president a useful campaign vote winner."

All of which makes him a key player, even though he is two years too young to contest a seat earmarked for him in the Bhutto family heartland of Sindh province.

"It is still too early. He is already the co-chair of the party, but he will enter full-time politics when he feels ready," said a party insider.